One issue that comes to mind is many door mounted components are designed to be mounted in several millimeter sheet metal, not something like 1/2" thk plywood.
That could be remedied with some sort of thin panel in a cutout in the door.
I wouldn't shy away from wood, its not a typical material for electrical enclosures, but really, it doesn't make it dangerous.
I think a well crafted wooden enclosure would be pretty interesting, with a proper finish it would standup well in the brewery environment. At that level, you may end up spending more time + money with wood, then just going with an off the shelf enclosure, so if your just looking to do it cheap, it might not be the best route.
Actually, way back in the day (75 yrs ago), the company I work for used to use wood as an insulating and structural support material for copper bus within power distribution system.
